line-parser

A line parser for Java based on mmap()

License	MIT
GroupId	com.github.marschall
ArtifactId	line-parser
Last Version	0.5.0
Release Date	Aug 17, 2017
Type	jar
Description	line-parser A line parser for Java based on mmap()
Project URL	https://github.com/marschall/line-parser
Source Code Management	https://github.com/marschall/line-parser

Download line-parser

Filename	Size
line-parser-0.5.0.pom
line-parser-0.5.0.jar	11 KB
line-parser-0.5.0-sources.jar	9 KB
line-parser-0.5.0-javadoc.jar	29 KB

How to add to project

Apache Maven

<!-- https://jarcasting.com/artifacts/com.github.marschall/line-parser/ -->
<dependency>
    <groupId>com.github.marschall</groupId>
    <artifactId>line-parser</artifactId>
    <version>0.5.0</version>
</dependency>

Gradle Groovy

// https://jarcasting.com/artifacts/com.github.marschall/line-parser/
implementation 'com.github.marschall:line-parser:0.5.0'

Gradle Kotlin

// https://jarcasting.com/artifacts/com.github.marschall/line-parser/
implementation ("com.github.marschall:line-parser:0.5.0")

Apache Buildr

'com.github.marschall:line-parser:jar:0.5.0'

Apache Ivy

<dependency org="com.github.marschall" name="line-parser" rev="0.5.0">
  <artifact name="line-parser" type="jar" />
</dependency>

Groovy Grape

@Grapes(
@Grab(group='com.github.marschall', module='line-parser', version='0.5.0')
)

Scala SBT

libraryDependencies += "com.github.marschall" % "line-parser" % "0.5.0"

Leiningen

[com.github.marschall/line-parser "0.5.0"]

Dependencies

test (4)

Group / Artifact	Type	Version
junit : junit	jar	4.12
org.openjdk.jmh : jmh-core	jar	1.19
org.openjdk.jmh : jmh-generator-annprocess	jar	1.19
org.openjdk.jol : jol-core	jar	0.8

Project Modules

There are no modules declared in this project.

line-parser

<dependency>
    <groupId>com.github.marschall</groupId>
    <artifactId>line-parser</artifactId>
    <version>0.5.0</version>
</dependency>

An mmap() based line parser for cases when:

• the start byte position of a line in the file is required
• the length in bytes of a line is required
• only a few character of every line are required

In these cases this library can theoretically be more efficient than BufferedReader because:

• the copy operations of buffered IO are avoided
• the allocation and resizing of an intermediate StringBuffer is avoided
• the allocation of the final String is avoided, only the required substrings are allocated

The performance may still be slower than a than BufferedReader based approach but it should consume much less memory bandwidth and produce only a fraction of the garbage.

As this project gives you a CharSequence instead of a String you may want to have a look at the charsequences which gives you some the String convenience methods while avoiding allocation.

Misc

• the main parsing loop is likely to benefit from on-stack replacement (OSR)
• if you're using UTF-8 with a BOM then the BOM is returned as well
• if you're using UTF-16 with a BOM then the BOM is returned as well
• the library runs on Java 8 but is also a Java 9 module that only requires the jdk.unsupported module besides the java.base module

Usage

LineParser parser = new LineParser();
parser.forEach(path, cs, (line) -> {
  System.out.printf("[%d,%d]%s%n", line.getOffset(), line.getLength(), line.getContent());
});

Versions

Version
0.5.0 Aug 17, 2017
0.4.2 Jul 3, 2017
0.4.1 Jul 3, 2017
0.4.0 May 7, 2017
0.3.0 Feb 17, 2017
0.2.0 Feb 5, 2017
0.1.0 Aug 6, 2016